Nanoceramic Coating for Next-gen Nuclear Reactors
Chuck Heschmeyer | December 14, 2016An international team of researchers has created a nanoceramic material that can withstand the effects of radiation and tougher under that radiation.
The material, developed by engineers at the University of Wisconsin-Madison and their collaborators at the Italian Institute of Technology in Milan, is an aluminum oxide nanoceramic coating that can withstand the effects of high-temperature liquid metals in advanced nuclear reactors.
Researcher Alexander Mairov in the ion-beam lab. Credit: University of Wisconsin-MadisonTraditionally, water has been used as the primary coolant in reactors, absorbing the heat released from fission reactions, according to researchers. Although water poses fewer risks of corrosion damage to materials, there are limits to the top temperatures at which water-cooled reactors can operate. New coolants, such as liquid metals like sodium and lead, are effective at much higher temperatures, but also are much more corrosive to the reactor.
“There is a preferred use of metallic materials for structural components, but many of these materials cannot withstand high-temperature corrosion in advanced reactors,” says Kumar Sridharan, research professor in engineering physics and materials science and engineering at the University of Wisconsin-Madison. “Corrosion is a surface phenomenon, so if you put coating on the surface, you need that coating to withstand high radiation doses without becoming embrittled.”
Many materials tend to harden and crack when exposed to radiation. But aluminum oxide nanoceramic coatings toughen, ultimately benefiting from irradiation, says Fabio Di Fonzo, team leader at the IIT Center for Nano Science and Technology, whose lab is focused on producing aluminum oxide nanoceramics.
The Wisconsin researchers used transmission electron microscopes to conduct microscopy analysis of the coatings to gain a more thorough understanding of their properties.
“The pinpoint of our work is the demonstration that an amorphous or nanoceramic material can improve during irradiation, and this opens the path toward a different view of nuclear materials, specifically where coatings are concerned,” Di Fonzo says.
Researchers anticipate that the nanoceramic material will be able to make next-generation reactors safer and more economical.